Speed governor for revolving doors



May 5, 1925. 1,536,197 H. w. DVYER SPEED GOVERNOR FORBEVOLVING DOORS Fild May 5., 1924 1 \d, 29 --/4 1 22 mm lk\\\\l 4141A TTORNE f Patented May 5, 1925.

UNITED STATES HARRY W. DYEB, OF NEW YORK, N. Y.

' SPEED GOVERNOR FOR REVOLVING DOORS.

' Application filed May 5, 1924. Serial No. 711,284.

To all whom it may concern. I

Be it known that I', HARRY V. DYER, a citizen of the United States, and resident of 250 lVest 51th Street, New York, in the county of New York-and State of New York, haveinvented certain new and useful Speed Governorsfor Revolving Doors,

of which the followingis a specification. This invention relates to revolving doors and particularly to a governor for doors of this class for controlling their speed of rotation and it has for an object to prevent doors of this class from rotating above a predetermined speed and a further object is to provide a speed governor for revolving doors of the standard type without interfering with their construction and operation. Other objects of the invention will be understood from the following specification and the accompanying drawings in which Fig. 1, is a plan view of a revolving door showing the mechanism at the top of the door, Fig. 2 is a side elevation showing the mechanism at the top of the door and Fig. 3 is a. detail, partly in section, showing the construction of the governor. 4

Revolving doors according to standard practice are placed in a semi-cylindrical entrance with a vertical shaft in the centre supporting four or more wings which rotate with the shaft and form-compartments by means of which a person may enter on one side or leave on the other side of the shaft as it rotates. These doors are rotated by the person entering or leaving the building and owing to their momentum they continue to rotate after the persons has passed through the door.

The wings of these doors are collapsible so that in an emergency they can be folded together and the entire entrance may be used for trafiic in both directions. The centre shaft may, also, be moved to the side affording a free and unobstructed passage to the building.

A person passing rapidly through a. door of this type naturally rotates it at a higher speed than a person walking slowly through the door. In practice it is found that 12 R. P. M. is a convenient speed-of rotation but speeds in excess of 15 R. P. M. are annoying to a slowly moving passenger and the present invention is designed to prevent a predetermined speed being exceeded.

In applying this invention the normal operation of the door or the movement of the centre shaft is not interfered with, no gears are used and the device is designed to work with as little noise and wear as possible.

The present invention comprises one or more arms secured to the end of the door shaft. The outer end of each of these arms is inclined upwards and carries a friction wheel and weights acting against a spring. Normally these arms and the friction wheels on the endiof the arm stand clear of the roof of the door but when a predetermined speed is exceeded the weights move the friction wheels outward up the inclines until it engages the roof and are thereby rotated. A

spring brake is applied to the side of this wheel so that it offers considerable resistance to rotation where it engages the roof and thereby acts as a brake. The length of the brake arms and therefore the angular speed of the weights can be regulated so that the device becomes efiective at the predetermined speed when rotated at the speed I of the shaft and without the use of gearing.

Referring to the drawings 1111 represent the cylindrical sides of the door opening, the leaves of the door are indicated by 12 and are mounted on the disc 15 mounted on shaft 14. These leaves arespaced 90 apart by the connections 13. The shaft 14 is suspended from the bearing 16 which is mounted through the frame 17 on the rollers 18 and 19 which are arranged to roll along the channel irons 20 and 21.

The shaft 14 is hollow and contains the rod 25 which, when raised, is released from the floor plate 24 and, releases the shaft at the bottom. This rod also raises the collar 26 through the slot 27 where a connection is made between 25 and 26. Collar 26 raises the lever 28 which is pivoted at 29 to the frame 17 and unlatches 30 from the locking bar 31. This permits the frame 17 to move on the rollers 18 and 19 along the channel irons to the extent of the slot 22 in the top of the door 23. The door with its leaves folded and moved to one side as described is shown by the dotted outline at 12, Fig. 1. When the centre shaft is restored to the centre position and 1'od25 lowered this shaft is locked at the bottom and the frame is latched at 31.

In applying the present invention to doors of this class the shaft 14 is extended as shown and the arms 35 and 36 are secured to this extension and move with the shaft as it rotates and as it moves from the centre,

these arms must therefore stand clear of the roof 44.

Thebrake arms are constructed asshown in Fig. 3. The end sections are deflected upwards as at a and are formed with splines 37 upon which the weights 38 slide by centrifugal action but do not rotate. Sleeves 39 extend from the weights 38 and are opposed by the coil springs 42 and the nuts 43. The friction wheel 41 is mounted to rotate upon the sleeve 39 but its rotation is retarded by the brake sprin 40 secured to the weight and engaging t e side of the friction wheel. A fibre washer may be provided on the side of this wheel to take up the wear.

As the door is rotated the weights, being subject to centrifugal action, move outward and oppose the springs 42. This moves the friction wheel outwards and up the inclined arm until it engages the plate 45 in the roof. This introduces a retarding action, however, it is preferable that the friction wheels rotate when they engage th roof, otherwise they would wear flat sides in a short time.

These wheels are therefore adjusted to rotate when they engage the roof but their movement is retarded by the brake springs 40 which exercise braking action on these wheels proportional to the centrifugal force exerted by the weights 38. When the speed falls below the predetermined value the springs 42 force the weights and the friction wheels back on the inclines and the brake arms are free of the roof.

In Fig; 2 the brake is shown as comprising two arms but three or more arms may be used as required. The weights 38 may be increased as necessary and the tension on springs 42 adjusted to make the device operative at the predetermined speed. This device is comparatively inexpensive and can be applied to doors of standard construction with comparatively little change in design. 1

Having thus described my invention, I claim:

1. A braking device for a revolving door comprising a horizontal arm fixedly secured to and revolving with the vertical shaft of said door, a' weighted member movably mounted on said arm a fixed frame for said door, said member arranged to move into engagement with said frame when said door exceeds a. predetermined speed.

2. A braking device for a revolving door comprising an arm secured to and revolving with said door, the end of said arm being deflected and supporting a 'movably mounted wei ht, a fixed frame for said door and means or brin ng'said weight into engagement with saicFframe when said door exceeds a predetermined speed.

3. A braking device for a revolving door, revolving in a fixed frame, comprising an arm secured to and revolving with said door, a friction wheel on said arm and centrifugal means for bringing said friction wheel into engagement with said frame when said door exceeds a predetermined speed.

4. In a braking device of the class described, the combination of a revolving door revolving in a fixed frame and having a centre shaft capable of moving to the side of said frame, a braking arm secured to said shaft and free of said frame and means for bringing said arm into engagement with said frame when said door exceeds a predetermined speed.

5. In a braking device .of the class described, the combination of a revolving door revolving in a fixed frame about a centre shaft, an arm rotating with said shaft, a

weight and a friction wheel at the end of said shaft arranged to slide on a portion of said shaft deflected from the horizontal, said wheel being brought into engagement with said frame by centrifugal action when said arm rotates above a predetermined speed.

6. In a braking device of the class described, the combination of a revolving door revolving in a fixed frame about a centre shaft, an arm'rotating with said shaft, a weight and a friction wheel slidably mounted on the end of said arm, said weight held against rotation, a brake sprin interposed between said weight and sai wheel and means for brin ing said wheel into engagment with said rame when said arm rotates above a predetermined speed:

Signed at New York in the countywof New York and State of New York this 28th day of March A. D. 1924.

HARRY W. DYER. 

